Driving and indication apparatus



Oct. 22, 1957 G. J. KENNEDY DRIVING AND INDICATION APPARATUS Filed Dec. 30, 1955 m w m m GILBERT II KfN/VED) ited States Patent" 2,810,292 V DRIVING AND INDICATION APPARATUS Gilbert J. Kennedy, Philadelphia, Pa., assignor to Philco Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application December 30, 1955, Serial No. 556,732

Claims. (Cl. 74--10.5)

The present invention relates generally to differential drive mechanisms and pertains more particularly to apparatus for driving at predetermined different speeds and including indicating means for giving certain desired information. Specifically, the invention has to do with improvements in rotary drive and dial arrangements which, although suitable for use with various kinds of rotatably driven devices, is especially useful when employed as means for effecting and indicating adjustments of channel selectors or tuners of the type commonly employed in television receivers.

, According to present practice, most television tuners are constructed and operable for rapid adjustment to any one of several pre-established positions each correspond ing to a different television channel. This rapid adjustment effects coarse tuning that is tuning of the television receiver roughly to a desired channel. These tuners are also constructed and operable for slow adjustment, following coarse tuning to a selected channel, such slow adjustment effecting fine tuning that is tuning of the receiver precisely to the selected channel.

Tuners of the above mentioned variety are driven by means of manually actuated instrumentalities which preferably and'usually are rotatable in both clockwise and counter-clockwise directions and, for convenience and ease of operation, it is desirable that the rotation of the tuner drive, in both directions and for both coarse and fine tuning, be accomplished through manipulation of a single actuator or knob. However the provision of a drive utilizing a single knob for effecting coarse and fine tuning in two directions, has given rise to manufactun ing complexities and problems, particularly when attempting to combine such a drive with a channel indicating dial.

Accordingly it is an object of the present invention to overcome the above mentioned complexities and problems by providing a novel and simplified reversely rotatable drive arrangement whereby coarse and fine tuning, as well as channel indication, is readily obtained through manipulation of a single actuator or knob.

It is also an object of the present invention to provide an improved combination of driving elements cooperating to produce a differential drive without gear trains, cord-and-pulley arrangements, or like motion transmitting systems.

A characteristic feature of the invention resides in the provision of a device which combines reversible differential drive means and channel indicating means and which,

can be directly connected with the actuating shaft of a conventional tuner to adjust the same in various predetermined positions for the reception of available television channels. r

The invention is further characterized by the provision of -a compact article of manufacture which incorporatessimply constructed and assembled rotatable elements for indicating selected television channels, as well as for driving the actuator of a television tuner.

Generally stated, the-above noted objects and features Patented Oct. 22, 1957 of the invention are achieved by utilizing a simple mechanical linkage between a rotatable driving shaft and a prime mover element. The driving shaft and prime mover element are mounted for relative rotational movement, and said element is operatively associated with the mechanical linkage to transmit rotary motion to said shaft at a rate either approximately equal to or substantially'less than the rotational speed of said element.

According to a specific embodiment of the invention, the prime mover element serves as a manually operable knob and the mechanical linkage incorporates a rotary operating member which functions as an indicator or dialfor indicating the angular position of the aforesaid driving shaft.

The invention, its objects, features and advantages,

will be more fully understood from the following detailed description considered with the accompanying drawing in which:

Figure l is a front elevational view of a television receiver supplied with tuner-driving and channel-indicating apparatus constructed in accordance with the present invention;

Figure 2 is an enlarged fragmentary sectional view taken substantially on line 22 of Figure 1;

Figure 3 is an elevational sectional view looking in thegeneral direction of arrows 3-3 of Figure 2 with portions broken away and removed, and illustrating certain driving members under one operating condition;

Figure 4 is a view similar to Figure 3 with the illustrated driving members in another operative position; and

Figure 5 is a sectional view taken substantially on line 55 of Figure 4, and illustrating the cooperative interengagement of associated driving members.

As indicated hereinabove, the apparatus of the present invention may be utilized with various types of devices. However, because the principles of the invention are particularly applicable to television channel selectors or tuners, the specific embodiment herein given by way of example, is illustrated and will be described in connec tion with a television receiver.

.Having more particular reference to the drawing, there is illustrated in Figure 1 a conventional television receiver cabinet 10 having a front wall 11 provided with a viewing opening 12 in which is fitted the usual protective transparent panel 13. Various controls of the receiver, including a channel selector control device 14, are conveniently arranged on the front wall 11 of the cabinet. As shown in Figure 2, the cabinet 10 encloses a chassis 15 which is of usual construction and carries the customary electronic components including a channel selector or tuner 16. This tuner is of conventional type adapted for adjustment to the desired channel by rotation of an actuating shaft 17 driven through manipulation of the control device 14'.

In accordance with the invention and as best seen in Figure 2 of the drawing, the control device 14 comprises a drive shaft 18 having an enlarged end portion 19. This end portion of the drive shaft 18 passes into the cabinet it) through an opening 26 in the front wall 11 of said cabinet, and is formed with an axially disposed bore 21 which receives an end portion of the tuner actuating shaft 17. Suitable means, such as set screw 22, serves to interlock the shafts so that they can rotate together. A bushing" 23 is rotatably mounted on the drive shaft 18 and sup ports a pair} of frictionally engageable clutch plates 24 and 25, each provided with an apertured portion for receiving said bushing.

As shown in Figure 2, the apertured portion of the rotation about said bushing. A comically QildPIil1gQ bears against an upstanding circumferential flange 31 on the bushing 23 and against the clutch plate 25 to urge the latter in a direction for face-to-face frictional engagement with its companion clutch plate 24, As a result, the rigidly interconnected bushing 23 and clutch plate 24 are effectively held against rotation about the drive shaft 18 so long as said plate v24 is not subjected to a rotational force sutficient to overcome the restraining frictional force mpo d by t e Sp ng-ur d c ut h pl As seen in Figure 2 of the drawing, the clutch plate 24 is provided with a marginal extension 32 to which a link 33 is swingably connected as by means of a pivot pin 34 passing through said extension 32 and through one end of portion 35 of said link. Thus the clutch plate 24 provides a support for mounting the pivot of the link 33 said support being capable of. rotating with respect to the rotatable drive shaft 18, in the manner and for the purpose to be described hereinafter. The other end portion 36 of the link 33, as more clearly appears in Figures 3 and 4, is disposed between and contacts a pair of confronting bosses37 rigidly formed on a dial member 38 which as represented at 38a is keyed or otherwise affixed to the drive shaft 18. The dial member 38 is provided with suitable customary channel-indicating index means, represented at 38b in Figure 1.

Movement is imparted to the link 33 by actuation of a prime mover element which, as illustrated, is a manually operable driving knob member 40 rotatably mounted on a forward end extension 41 of. the drive shaft 18, said driving knob member and link having interengageable means whereby motion is imparted to the latter to rotate said drive shaft. For that purpose, the rearward face of said driving knob member 40 has a cam track in the convenientforrn of an eccentric groove 42 which engages a cam follower, such as a stud 43 secured to an intermediate portion of the link 33 and passing through an elongated slot 43a in the dial knob "member38. The member 40 is retained in axial position on the' forward end extension 41 of the drive shaft 18 by means of a washer 45 and .a locking element 46 in engagement with said end portion of said shaft. A coil spring 47 bears against the washer 45 and knob member 40 and forceably urges the latter into position for maintaining said cam groove 42 and said stud 43 in riding engagement. The groove 42 terminates with closed end portions 42a and 42b to abut the stud 43 as illustrated in Figures 3 and 4.

Means is advantageously provided to stabilize the link 33 and to insure its retention between the bosses 37. As best seen in Figure 2, such means may conveniently be in the form of lateral projections 48 and 49 extending from opposite sides of said link to bear, against the dial member 38 and the rotational clutch plate 24. In this manner, projections 48 and 49 cooperate with the pivot pin 34 to maintain the link 33 in approximate parallelism with respect to said dial member 38 and clutch plate 24.

The knob member 40 is advantageously provided with an extended annular portion 50 for easy manipulation.

A suitable cover 51, adapted for snug engagement with.

said annular portion, imparts a finished appearance to said knob member.

The operation of the control device 14 will be bestunderstood by referring to Figures 3 and 4 which illustrate the two extreme positions to which the link 33 is swung by cooperative function of the stud 43 and groove 42.

From Figure 3 it will be understood that when theknob member, is manually rotated in the direction represented by arrow A to bring the closed end portion 42a of the eccentric groove in contact with the stud 43, continued rotation of said knob member in that direction subjects the link 33 to a rotational force in that same general direction. This rotational force onthe link 33 reacts through the, pivot 34 to overcome the frictional restraint which is imposed on the rotational clutch plate 24 by the non-rotational clutch plate 25, as hereinbefore described with reference to Figure 2. During this condition of operation, the clutch plate 24, link 33, dial member 38,

tricity of said groove.

interlocked shafts 18 and 17, and knob member 40, in effect, become a rigid unitary system which rotates about the axis of rotation of said shafts and at the rate of speed at which said knob member is manually rotated, to effect coarse tuning. During this rotational motion, the fixed or non-rotatable clutch plate 25 constantly acts to maintain the slipping clutch plate 24, together with the link 33 and dial member 38, in whichever angular position it attains when manual rotation of the knob member 40 ceases.

However when the knob member is manually rotated in the reverse direction, that is in the direction indicated by the arrow B in Figure 3, the closed end portion 42a of the groove 42 leaves the stud 43. When this condition occurs and the knob member is rotated in either direction, the cam groove 42 causes the link 33 to swing on the pivot 34 and transversely of the axis of rotation of the interlocked shafts 18 and, 17. During this swinging movement, the link 33 imparts no rotational force to the. clutch plate 24 so that the latter is held stationary by the frictional action of the clutch plate 25. Under this condition of operation, the dial member 38 and interlocked shafts 18 and 17 are rotated at reduced speed with respect to the rotation of the knob member, to effect fine tuning in response to sait swinging movement of the link 33 within a limited tuning range represented at R.

Rotation of the knob member in the direction represented by arrow B eventually swings the lever 33 to the position illustrated in Figure 4, in which position the other closed end portion 42b of the groove 42 contacts the stud 43. When this occurs and manual rotation of the knob member is continued in the direction of arrow B, the link 33, clutch plate 24, dial member 38, interlocked shafts 18 and 19 and knob member 40, again become a rigid unitary system which rotate in the manner above stated but in the direction of arrowB, toeifect coarse tuning in that direction. However under this latter condition, when the knob member is manually rotated in the other direction, that is in the direction of arrow A in Figure 4, the closed end portion of 42b of the eccentric groove 42 leaves the stud 43, whereupon rotation of the knob member in either direction, againcauses said groovetoswing the.

link 33 about the pivot 34 as and for the purpose above stated.

It will be noted from Figures-3 and 4 that the angular swinging displacement of the link 33 determines the time tuning range R, and it will be understood that the extent of this angular displacement depends upon the length of cam groove 42 and that the speed at which said link is swingably displaced depends upon the degree of eccen- In other words, the angular swinging displacement of the link 33, and therefore the range of fine tuning, can be made either smaller or greater by either shortening or lengthening said groove, whereas the rate of movement of said link, and therefore the fine tuning speed, can be made either faster or slower by. either increasing or decreasing the eccentricity of the groove 42.

From the foregoing description it will be appreciated that the invention provides a compact self-contained unit, which combines means for drivingly adjusting a control device at differential speeds and means for giving indication of the adjustments of said device. Although the invention has been shown and described with reference to a specific embodiment, it will be understood that this embodiment is susceptible to structural variation without departing from the gist of the invention. For example the connection between the driving and the driven shafts, the connection between the clutch plate assemblyand the cabinet front, and the connection of the clutch assembly and dial member with the link, could be obtained otherwise than herein shown and described, as by utilization of suitable known fastening procedures. Also, the manner of stabilizing the link with respect to its associated components may be accomplished without the laterally extending projections on said link, simply by placing suitable spacer means for filling in the gap or gaps between said link and the adjoining elements. Moreover, if desired, the shaft on which the clutch assembly, dial member and actuating knob member are mounted, could be made an integral part of the tuner actuating shaft or other element to be rotatably driven for coarse and Vernier adjustments.

I claim:

1. In combination with a device adapted to be rotatably driven, a differential drive comprising a rotatable shaft for driving said device, a link element drivingly connected with said shaft, a pivot for said element, means mounting said pivot for displacement together with said link element about the axis of rotation of said shaft, said means also mounting said pivot to support said link element for swinging motion transversely of the axis of rotation of said shaft, and a prime mover element mounted rotatably with respect to said shaft, said prime mover and link elements having interengageable means which under one condition of operation imparts said displacement to said pivot and link element for driving said shaft at approximately the same rotational speed as the rotational speed of said prime mover element and which under another condition of operation imparts said swinging motion to said link elements for driving said shaft at a rotational speed slower than the rotational speed of said prime mover.

2. The combination set forth in claim 1, in which a rotatable member provides the driving connection between the mentioned link element and the mentioned shaft, said member being rigidly anchored on said shaft and having means for indicating the angular position of the latter.

3. The combination set forth in claim 1, in which a support mounted rotatably with respect to the mentioned shaft provides the means for mounting the mentioned pivot, and in which means is provided for restraining said support against rotation While the mentioned prime mover element imparts the mentioned swinging motion to the mentioned link element.

4. The combination set forth in claim 3, in which the mentioned support is mounted rotatably on the mentioned shaft, and the mentioned restraining means includes a friction element held against rotation on said shaft and resiliently urged into frictional engagement with said support.

5. The combination set forth in claim 1, in which the mentioned interengageable means between the mentioned prime mover and link elements includes a cam track on one of said elements and a cam follower on the other of said elements.

6. The combination set forth in claim 5, in which the mentioned cam track is in the form of an eccentric groove having closed end portions, and the mentioned cam follower is in the form of a projection extended for riding engagement with said groove and for abutting engagement with said closed end portions.

7. The combination set forth in claim 5, in which the mentioned prime mover element provides a manually operable knob, the cam track is provided on said knob and is in the form of an eccentric groove having closed end portions, and the mentioned cam follower is provided on the mentioned link element and is in the form of a projection extending therefrom for engagement with said groove and with the closed end portions thereof.

8. In a television receiver, a control including shaft means for adjusting said receiver to different television channels, frictional clutch means mounted to rotate with respect to said shaft means, linking means carried by said clutch means and mounted thereon to swing with respect thereto, osition indicating means rigidly connected with said shaft means and engaging said linking means, driving means rotatable with respect to said shaft means, abutting means disposed on said driving means for engagement with said linking means to drive said indicating means and shaft means at a speed corresponding to the speed at which said driving means is rotated, and cam means disposed on said driving means for engagement with and for swinging said linking means with respect to said clutch means to drive said indicating means and shaft means at a speed slower than the speed at which said drive means is rotated.

9. In a television receiver, the combination of a channel selector provided with a rotatable element for adjusting said selector in different positions to effect channel selection, a drive shaft connected with said element, a rotatable clutch plate mounted on said shaft to rotate thereon, a slidable clutch plate mounted on said shaft for frictional engagement with said rotatable clutch plate, a dial member aflixed to said shaft, a manually rotatable knob mounted on said shaft to rotate thereon and having a I cam groove terminating with closed end portions, a link swingably connected to said rotatable clutch plate, means for drivingly coupling said link with said dial member, and a cam follower carried by said link and engaging said groove.

10. In a television receiver, the combination of a channel selector provided with a rotatable element for adjusting said selector in diiferent positions to eifect channel selection, a drive shaft connected with said element, a rotatable clutch plate mounted on said shaft to rotate thereon, a slidable clutch plate mounted on said shaft to slide longitudinally thereof, means for resiliently urging said slidable clutch plate into frictional engagement with said rotatable clutch plate, a dial member affixed to said shaft and having a slotted portion, a manually rotatableslidable knob mounted on said shaft to rotate thereon and to slide longitudinally thereof, said knob having a cam groove terminating with closed end portions, an elongated link positioned between said dial member and said rotatable clutch plate, pivot means for swingably connecting one end portion of said link to said rotatable clutch plate, means for drivingly coupling the other end portion of said link with said dial member, a cam follower carried by an intermediate portion of said link and extending therefrom through said slotted portions of said dial member and into engagement with said groove, means for resiliently urging said knob in a direction to maintain said groove in riding engagement with said follower, and means provided on said link and engageable with'said dial member and with said rotatable clutch plate, said last named means cooperating with said pivot means to stabilize said link.

References Cited in the file of this patent FOREIGN PATENTS 609,651 Great Britain Oct. 5, 1948 

